Another prominent Republican Alaska legislator has been criminally charged for his role in a massive bribery scandal that has already landed a pair of politicians in jail and led to the convictions of two oil executives who have admitted bribing numerous lawmakers.

The latest to fall in the widespread corruption ring is state Senator John Cowdery, the oldest member of the Alaska Legislature and onetime chairman of the state’s powerful Rules Committee. A 16-page indictment accuses Cowdery of scheming with oil company executives to buy the vote of another senator to obtain an oil tax that would financially benefit the company.

Two executives of the company, Veco Corp., have already been convicted of bribing Alaska lawmakers and are assisting the government in the never ending probe. Veco, which has raked in tens of millions of dollars in government contracts over the years, had stood to benefit financially if the Alaska Legislature passed a new oil tax in 2006 so the company started dishing out cash to buy legislators’ votes.

Two disgraced lawmakers—former House Speaker Pete Kott of Eagle River and Wasilla Representative Vic Kohring—have been convicted on corruption charges related to the push for the tax and are serving federal prison sentences. Another (Juneau Representative Bruce Weyhrauch) has been charged and is awaiting trial.

The investigation started about two years ago when FBI agents raided the offices of half a dozen Alaska lawmakers, including Cowdery and others who have subsequently been indicted. Not surprisingly, all the elected officials have vehemently denied any wrongdoing. Now the veteran lawmaker faces up to 15 years in prison and a half a million-dollar fine. His first court appearance is scheduled for the middle of next month.

The scandal is not limited to the state’s local lawmakers. U.S. congressman Don Young and U.S. Senator Ted Stevens, Alaska’s most powerful political figure, have also been linked to the bribery operation. In fact, federal agents raided Stevens’ home last year because Veco founder Bill Allen oversaw the costly renovation of the senator’s home near Anchorage, which authorities say could have been used to bribe the lawmaker who has represented Alaska in Washington since 1968 and is the U.S. Senate’s senior Republican.